Nine out of ten women find asking for money – i.e., a raise – embarrassing, according to a survey out this morning from Sheconomics.com. This compares to six out of ten men. And women are two and a half times more likely than men to find negotiating for pay humiliating.

Humiliating?

Embarrassing?

How about necessary and – when it goes well – empowering?

Last week, the headlines shouted the fact that women had caught up in the education race. We’re now just as likely to earn bachelor’s degrees as men are. (In fact, because there are more of us walking the planet, there are 1.6 million more women with these diplomas than there are men.) We’re more likely to amass graduate degrees. And yet the needle has hardly budged on the cents a woman earns per dollar a man does. For years it stood at 77 cents. Recently it jumped to 81 cents. Woo-hoo.

Here’s a hint: It’s not going much higher unless we start asking for what we’re worth. The Sheconomics research noted that in the past six months one-third of the men surveyed had asked for a raise. Fewer than one-quarter of the women had done the same. If you don’t ask, the answer will always be no.

So how do you get yourself there? First, do your homework. Women – more than men – feel more comfortable knowing what the right answer is before we ask the question. That’s why we do everything from cooking with recipes to doing more research than men before we buy a stock or mutual fund. In the job market, the equivalent is knowing your value in the marketplace. And women don’t study that enough.

Lisa Barron, a professor of organizational behavior at the University of California, Irvine, put MBA students through a series of mock job interviews. Barron set it up so that every one of those students did well enough in the interview to merit not only a job offer – but the same job offer. She offered each one the same position for an annual salary of $61,000. Then she sat back and waited to see what sort of counter-offering ensued. The men Barron interviewed asked for an average $68,500. The women for $67,000.

Now remember: These were students in the same program who had learned the same things and were graduating the same year. Why the discrepancy? Why did men feel they were entitled to $1,500 – on average – more than the women?

In fact, Barron learned, there were two things going on. The men, interviewed after the fact, said they believed they deserve to earn more money than the others – men and women – in their class. So to them it was natural to ask for a higher salary. The women said they felt they deserved to earn the same money as the others – men and women – in their class. So they didn’t want to overshoot. The other big difference: Four out of five of the men had studied the market enough to have a decent sense of their true value. Only one out of five women had done that.

Second, prepare your case. Telling your boss that you’d like a raise is like your child telling you she’d like another dessert. Of course you’d like a raise. So would the people in the next eight cubicles. The fact that you want a raise – or even need a raise – is beside the point. You need to show that you deserve a raise because you’re making the company money, saving the company money or worth a lot more on the open market (and therefore replacing you would cost the company money). And you do that by laying out the facts. Show your boss – on paper – how your new plan to keep the store open an extra hour on weekends has increased revenues or how the improvements you made to the database saves you and your colleagues time. To prove you’re underpaid pull together a folder of classified ads and jobs posted on the Internet – all of which you’re qualified for. Even call a headhunter or two to find out what people with your skills are fetching in the job market.

Finally, visualize the result. Wanting a raise isn’t specific enough. You need to know – going in – how much money you want to get out of this conversation. When your boss asks (as he or she undoubtedly will) what your number is, suggest one five to ten percent higher. That gives your employer room to negotiate. It’s not good for either side to feel they give in too easily. Also, enter this negotiation with a list of things you might be willing to accept other than money: more vacation, a title bump, the flexibility to spend part of your time working from home. Although the economy is doing better on average, your particular employer may not have enough wiggle room to give you a bump in salary. But that doesn’t mean you walk away empty-handed.